Kaga Onsen (加賀温泉) is a collection of four hot spring towns south of Kanazawa, not far from Mount Hakusan, one of Japan's "three holiest mountains" (alongside Mount Fuji and Mount Tateyama). The hot springs were discovered over 1300 years ago by monks visiting Hakusan, and have been popular, highly rated onsen destinations ever since.

A characteristic of Kaga Onsen's hot spring towns are their public baths (soyu), which are found in the center of each town. In the past, when not every ryokan had its own baths, staying guests would visit the soyu instead. These communal baths remain popular among visitors and residents alike, and can present tourists with a unique, local bathing experience.